I used to race with a club called NSRA (www.nsraracing.com) that runs winged sprint cars on asphalt tracks. Every once in a while, especially on the larger tracks and in colder weather, you'd see little condensation vortices (plural vortex) behind the tips of the wings. Even less often one could see a "pocket" of condensation just below the trailing edge of the wing. It kind of looks like a cloud, in a way. What causes that? Is it related to the vortices? I'd like to get pictures, but it happens so abruptly, and usually at night (not camera friendly, when the air is around 40-50 degrees farenheit).